diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 4ba0a73..952915f 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -2161,7 +2161,9 @@
 				    tx_sw_if_index0, &next_index, b[0]);
 	  next[0] = next_index;
 	  if (is_midchain)
-	    calc_checksums (vm, b[0]);
+	    vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
+					0 /* is_ip6 */ ,
+					0 /* with gso */ );
 	}
       else
 	{
@@ -2183,7 +2185,9 @@
 				    tx_sw_if_index1, &next_index, b[1]);
 	  next[1] = next_index;
 	  if (is_midchain)
-	    calc_checksums (vm, b[1]);
+	    vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
+					0 /* is_ip6 */ ,
+					0 /* with gso */ );
 	}
       else
 	{
@@ -2327,7 +2331,9 @@
 	  next[0] = next_index;
 
 	  if (is_midchain)
-	    calc_checksums (vm, b[0]);
+	    vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
+					0 /* is_ip6 */ ,
+					0 /* with gso */ );
 
 	  /* Guess we are only writing on simple Ethernet header. */
 	  vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
@@ -2426,7 +2432,9 @@
 
 	  if (is_midchain)
 	    /* this acts on the packet that is about to be encapped */
-	    calc_checksums (vm, b[0]);
+	    vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
+					0 /* is_ip6 */ ,
+					0 /* with gso */ );
 
 	  /* Guess we are only writing on simple Ethernet header. */
 	  vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index b7cdb1a..9c195e6 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1859,8 +1859,12 @@
 	    {
 	      /* before we paint on the next header, update the L4
 	       * checksums if required, since there's no offload on a tunnel */
-	      calc_checksums (vm, p0);
-	      calc_checksums (vm, p1);
+	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
+					  1 /* is_ip6 */ ,
+					  0 /* with gso */ );
+	      vnet_calc_checksums_inline (vm, p1, 0 /* is_ip4 */ ,
+					  1 /* is_ip6 */ ,
+					  0 /* with gso */ );
 	    }
 
 	  /* Guess we are only writing on simple Ethernet header. */
@@ -1955,7 +1959,9 @@
 
 	  if (is_midchain)
 	    {
-	      calc_checksums (vm, p0);
+	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
+					  1 /* is_ip6 */ ,
+					  0 /* with gso */ );
 	    }
 
 	  /* Guess we are only writing on simple Ethernet header. */